test: use latest MSTest

Author: richardschneider

test/IpfsHttpClientTests.csproj

@@ -9,9 +9,9 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.3.0-preview-20170628-02" />
-    <PackageReference Include="MSTest.TestAdapter" Version="1.1.18" />
-    <PackageReference Include="MSTest.TestFramework" Version="1.1.18" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" />
+    <PackageReference Include="MSTest.TestAdapter" Version="1.4.0" />
+    <PackageReference Include="MSTest.TestFramework" Version="1.4.0" />
   </ItemGroup>
 
   <ItemGroup>